Band-saw mill.



No. 629,849. Patent-ad Aug. 1, I899.

'E. E. FITZGERALD.

BAND SAW MILL.

(Application filed Aug. 22, 1898.

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. E. E. HTZGEBALD.

BAND SAW MILL.

(Application filed Aug-22 1898.; (No Model.) a Sheets-Sheet z.

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Patented Aug. I, I899.

- E. E.. FITZGERALD.

BAND SAW MILL.

(Application filed Aug. 22, 1898;;

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U ITED STAT-EST",

PATENT OFFICE.

EDWARD E. FITZGERALD, for MlLWAUKEE, WISCONSIN; ASSIGNOR or our- HALF TO TH EDWARD P. ALLIS COMPANY, or SAME PLACE.

BANo-sAwiMiLL.

SPECIFICATION forming part of Letters Patent No. 629,849, dated August 1, 1899.

Application tlel tu a 22, 1398.

Serial Nansen 44. (No model.)

To a-Z whom it may concern.-

Be it kn own that LED'W RD E. FITZGERALD, a citizen of the United Stated residing at'Milwankee, in the county of-Milwaukee and State of W'isconsim'have invented certain new and useful Improvements in Band-Saw Mills, of

which the following is a specification.

1 more particularly to the means for elevating and lowering the saw-carrying mechanism and maintaining it at the desired elevation.

Under the present invention I employ a cylinder and piston for elevating, lowering, and holdingat the required elevation the sawcarrying mechanism, employing in the cylinder any suitable pressure fiuid or liquid. In practice a hydraulic column is deemedbest; but air, steam, or gas may be utilized without departing from the spirit of my'invention or impairing the usefulness of'the'machine.

Other improvements consist in making the band-wheels with circumferential faces of less width than that of a newer full-width bandsaw and applying to the-rim removable filling-bands, which as the saw is reduced in width by filing or dressing may be removed,

so as to permit the blade to run properly on the wheels without injury to its teeth;

I propose also to provide the saw-blade with teeth on both its edges, so that a cut may be made on eachtravel' of the log-carriage forward orIbackward, thus utilizing the time now wasted, in gigging back the carriage.

Referring now to the accompanying drawings, Figure 1 is a front elevation of my improved mill, and Fig. 2 a side elevation of the same, both partially broken away to better show the construction of parts; Figs. 3, t, and 5, views illustrating the construction 8, an elevation showing in detail means for adjusting the rear bearing of the lower-bandwheel shaft for cross-lining. V

The construction of the framework and various of the details'of the mill may be considerably varied without departing from the spirit and scope of my invention; but the embodiment represented in the accompanying drawings is deemed advantageous on account of its simplicity, strength, and rigidity.

In the drawings, 1 represents the main floor of the mill; 2, a sawmill-carriage movable upon tracks or rails over said floor; 3, astrong' frame, here represented as of heavy timbers, but which may in practice be of metal, partly of wood and partly of metal, or, of any suitable rnateriah Resting upon the cross sills or timbers 4 of the fraui'ewo'rk 3 is an L-shaped base-frame 5, having three sockets in which are stepped or seated the lower ends of three vertical standards or guide-rods 6, 7, andS. The upper ends of these standards are carried and sustained by a casting 9, the baseof which spreads out. in rectangular formand rests upon sills or timbers at or near the line of the mill-floor, as shown in Figs. 1,2, and 6. The forward or main guiding-standards 6 and 7 extend upward some distance above the mill-floor, and the casting 9 has an upright portion 10, with overhanging projections 11 to receive and hold the upper ends of standards 6 and 7, as shown in Figs. 1 and 2. Said forward standards 6 and 7 are further supported and stiffened at points intermediate of their upper and lower ends by a casting 12, bolted or otherwise made fast upon the bed or casting 9 or otherwise secured upon the framing of the mill. This casting 12 has bosses or ears 13, which encircle the uprights or standards 6 and 7 as shown in Figs. 1 and 2, and prevent the springing or deflection of said standards under the strains brought upon the band-wheels, which receive their support from the standards. The manner of suppm t in g the guides or standards is, however, a matrco . rear guide-rod 8.

ter of detail, subject to variation, according to the ideas of the mechanic or mill-builder, and variable with the conditions of use; but it is deemed advantageous to give this intermediate support for the reason indicated.

Movable vertically upon the guides or stand ards 6, 7, and 8 is a frame 14, said frame comprising two distinct yokes 15 and 16, connected at their proximate ends by a right-and-left screw. Each yoke 15 and 16 is formed with four collars 17 to encircle the forward guiderods 6 and 7, each pair of collars playing upon a portion of the guide-rods between a pair of the sustaining-ears 11 and 13 of the main frame or between the lower cars 13 and the base-frame 5, as will be seen in Figs. 1 and 2. In this way adequate space is left for the vertical play of the frame 1 1, while the supporting-ears of the frame are enabled to hold the guide-rods at suitable and convenient intervals in their length.

The upper yoke 15 has the upper ends of its arms made of tubular form to receive the necks or stems 18 of vertically-movable boxsupports in which are pivotally carried boxes or bearings 19. These boxes are designed to support the opposite ends of an upper-bandwheel shaft 20, carrying a band-wheel 21. The sliding stems 18 of the box-supports are supported upon the pointed upper extremities of two-part rods 22. (Shown in full lines in Fig. 1 and in dotted lines in Fig. 2.) These rods are made in two parts and screw-threaded one into the other for the purpose of permitting them to be lengthened or shortened as occasion may require for purposes of adjustment. Each rod 22 rests upon one or the other short arm of a bifurcated lever 23, pivotallysupported upon the yoke 15 and carrying at the opposite side of its fulcrums a weight 24. (Shown in dotted lines in Fig. l and in plan View in Fig. 6.) This weight acting through the lever 23 is designed to exert an upward pressure through the rods 22 upon the boxes, the shaft mounted therein, and the band-wheel carried by said sh aft, which pressure is immediately applied to the band-saw passing about the wheel 21 and gives the automatic tension desirable in band-saw mills.

The lower yoke 16, instead of having its two arms alike, or essentially so, as is the case with the upper yoke 15, is formed with an outwardly or rearwardly extending arm 25. The outer or rear end of the arm 25 is provided with an opening to receive the upper end of a screw-threaded rod 26, which, passing through said perforation, is made fast to the arm 25 by nuts 27, secured upon the rod above and below said arm.

27 indicates a sliding yoke or bracket, the form of which is best shown in Fig. 8, and which is formed with a box to encircle the The bracket 27 is provided with an upwardly-extending arm, which is made fast to the lower end of the rod 26 by means of nuts 28, secured upon said rod above and below the perforated upper end of the upwardly-projecting arm of the yoke, as seen in Figs. 2 and 8. As a consequence of this construction the yoke or bracket 27 becomes, in effect, a part of the yoke 16. Its office is to carry a box or hearing 29, which, with a similar box 30, carried at the lower end of the forward arm of the yoke 16, serves to support the lower-band-wheel shaft 31.

The box or hearing 29 is supported upon a screw-threaded shaft 32, journaled in the bracketor yoke 27 and provided with abeveled pinion 33. Swiveled in an arm of the yoke or bracket 27 is a second pinion 34, meshing with the pinion 33 and serving when rotated to give rotary motion to the screwshaft 32, and thereby to move the box or hearing 29 laterally in the yoke or bracket 27, as will be readily understood upon referring to Fig. 8. Passing axially through the pinion 34: is a grooved or splined rod or shaft 35, which, receiving a feather or fitting a groove in the hub of the pinion 34, serves to impart motion to said pinion, while leaving the latter free to rise and fall independently of the rod. For the purpose of rotating the rod it is furnished at its upper end with a hand wheel 36, passing through a standard 37, which is split or slitted and provided with a screw 38, by which it may be contracted to clamp the rod 35 for the purpose of holding the-latter against accidental turning. In this way the pinions, and consequently the shaft 32, will likewise be held against rotation, and hence the box 29 will be precluded from shifting its position inopportunely.

The box or bearing 30 is carried in the forked end or yoke of a swiveled support or hanger 39, carried in the tubular lower end of the forward arm of the yoke 16 and held at the proper elevation therein by a threaded shank or stem 40, (shown in Fig. 1 and in dotted lines in Fig. 2,) said stern passing through a web of the yoke 16 and having nuts 41 screwed upon it above and below said web. The box 30 is pivoted in the yoke or fork of the support or hanger 39, and hence is free to rock or tip in a vertical plane, and by reason of the swiveling of the stem of said hanger or support in the yoke 16 said box may also be revolved in a horizontal plane about the axis of the hanger, while of course a compounding of these two movements affords adjustment in any desired direction. This or some equivalent mode of supporting the box 30 is rendered necessary in order to permit the lateral adjustment of box 29 through rotation of the screw-shaft 32 or the elevation or depression of said box 29 through the adjustment of nuts 27 or 28 on rod 26. The purposes of these adjustments are to illsure the running of the saw properly upon the band-wheel to effect cross-linin g or to tip the band-Wheel, so that the saw shall run nearer to or farther from the forward edge of the wheel. The elevation or depression of either end of the upper-band-wheel shaft 20 is efiec'ted by lengthening or shortening either from each other the upper and lower bandwheel shafts 20 and 31 to adapt the mill to receive saws of dilferent lengths. This provision is rendered necessary by the fact that saws even when new vary more or less in length and from breakage and rebrazin g. From insertion or removal of sections from time to time the length is changed and it is necessary to give to give to the wheels an initial adjustment appropriate to the particular length of the saw to be used. This of course is independent of the automatic tension ,or straining mechanism comprising the weighted lever 23, the movable box, and the intermediate connections, which automatic mechanism is designed to maintain a constant strain or tension upon the band-saw and to compensate for the slight variation in length incident to variations in temperature.

' The lower-band wheel shaft 31 carries a belt wheel or pulley 43, which receives motion through a belt from any convenient prime motor. It also carries a band-wheel 59.

At the working or forward side of the machine the saw-blade 44 passes through a guide composed of two members 45 and 46, the former resting directly upon the casting 9 and the latter upon a pivoted supporting-bar 47,

mounted Within the casting 9 and adjusted,

and held in proper relation to the member 45 by bolts, screws, or other suitable devices.

48 indicates the lo -carriage, which travels past the cutting side of the mill and is provided with head-blocks which, reaching over the guide 46 47, extend nearly, but not quite, to the line of the saw, as shown in Fig. 1. The position of the guide and the level of the log-carriage are constant. diameter of a piece capable of being sawed by the mill depends upon the distance between the level of the bed or floor of the logcarriage and the point above said level at which there is sufficient space between the band-saw and its wheel to permit the travel of the board, plank, or timber to be sawed from the log or cant, it being desirable always to have as short a length of free saw or blade above the lumber as is practicable. As set forth in my former patent, No. 491,047, hereinbefore referred to, the shortening of this space or of the free saw length above the lumher was the primary object of making the entire sawing mechanism vertically adjustable in its supporting-frame, and such is the purpose still in view. To facilitate such vertical adjustment of the mill to render it certain and expeditious, I now employ in con-- nection with the sliding mechanism a fluidpressure cylinder and a piston working within The thickness or said cylinder and connected with the sliding frame of the mill, the piston being moved upward, or upward and downward, if desired, by tluid-pressure,but sustained at any desired point by the fluid beneath it.

In practice I prefer to employa single-acting piston and to introduce the fluid-pressure beneath it only, permitting the mill or the movable portions thereof to settle back by gravity until the desired level is reached, whereupon, the escape of fluid being stopped or cut off, the entire movable structure will be sustained upon the fluid beneath the piston in said cylinder. This construction is illustrated in Figs. 1 and2, wherein 49 indicates a fluid-pressure cylinder provided with a three-way valve 50, which either opens communication between a fluid-pressure pipe 51 and the space below the cylinder or closes such communication and opens communica tion between said space and an exhaust-port 52. From the valve 50 a controlling-rod 53 or some equivalent device is carried to a convenient point for the operator or attendant, who through its aid may at any time effect the elevation or the lowering of themill.

Owing to the condensation of steam and the consequent difficulty of maintaining the piston and the parts supported by it at a fixed elevation, I prefer to use a liquid, such as water or glycerin, in the cylinder 49, said liquid being under suitable pressure applied in any of the common and well-known ways; but I do not mean to restrict myself to the use of liquids, since air, steam, or gases may be employed with results more or less satisfactory.

In practice it is found advantageous to partially counterbalance the mill or the movable mechanism thereof, leaving the same in the case of large log-mills out of balance to the extent of approximately a ton to a ton and a half. This amount of weight is suflicient to readily overcome the friction of the guiding-collars upon the guide rods or standards, which is necessarily considerable, since it is essential that there be no play or lost motion between these points. The partial counterbalancing, however, red uces the labor placed upon the fluid-pressure mechanism in elevatingthe movable mechanism of the mill.

Her'etofore it has been customary to make band-saws with teeth upon one edge only, and as a consequence it has been impracticable to cut on both the forward and rearward movement of the log-carriage. Hence .considerable time has been necessarily lost in gigging back preparatory -to a fresh out, It has been sought, however, to meet this difficulty by duplicating the mechanism and arranging two saws to run in the same plane; but aside from the ditficulty of giving to two blades running over separate pairsv of wheels such accuracy of adjustment as shall insure their traveling in absolutely the same plane that the inactive blade is liable to vibrate more than the active blade and to mar the faces of the board and cant or log. For this and other reasons, among which latter may be noted the'vastly-increased expense due to duplication of parts, it has not been found advantageous to attempt to out on both the forward and backward run of the carriage. I propose, however, to make the saw with teeth on both its edges, so that it may cut with equal facility whether the carriage be traveling in one or the other direction. This, however, requires certain special provisions beyond those found in band-saw mills as hitherto constructed.

It is of course well understood that in dressing band-saws and, in fact, saws of all types the teeth are swaged and broadened into chisel-like points the width of which insures a kerf sufficient to permit the free passage of the body of the blade without undue friction. In other words, the swaging of the teeth accomplishes, particularly in band and circular saws, essentially the same result that is attained by the set of teeth in common handsaws and the like. Obviously the teeth thus swaged should not be allowed to rest upon the periphery or rim of the band-wheel, but should be permitted to project beyond the edge thereof, so that while the main body of the saw gets a full and fair hearing or support upon the wheel the teeth projecting beyond the wheel shall not be bent out of shape nor the sharp cutting-edges of the swaged points dulled or in any manner impaired. It is, however, necessary to file and gum the saw-blades from time to time, and consequen tly their width gradually lessens, so that while in its original condition or of full width the blade might rest upon the wheel, with its toothed edges protruding beyond the edges of the rim, such would not be the case with a blade narrowed by repeated dressing or sharpening. To meet this difficulty, the bandwheels are formed as illustrated in Figs. 3, 4, and 5that is to say, each rim is circumferentially rabbeted or grooved at or near each edge, as indicated at 54, and the space thus formed is filled in the first instance by a removable band 55, which may be of any suitable material, and shrunk inplace or otherwise made fast, the mode of securing depending, of course, in greater or less degree upon the material of which the band is made. In practice I deem it advisable to make it of iron or of a mild steel and to shrink it in place. Fig. 3 shows the wheel in its first condition, with the bands 55 in position and the saw projecting at its edges beyond both faces or edges of the wheel, while Fig. 4 shows the saw reduced in width and the bands removed to permit the teeth to protrude beyond the suptravel of the log carriage. The economy thus attained is very great.

56 indicates an inclined block or chute lying close to the inner side of the saw-blade just above the point at which it approaches the rim of the lower wheel and serving to deflect and carry away from between the saw and the wheel the sawdust, splinters, &c.,

-moving downward with the blade and which entering between the saw and the wheel might subject the blade to sudden and undue strain or cause it to run off the wheel. The block 56 is supported by a bracket-arm 57 and a brace 58, secured to the lower yoke 16, though it may be carried in any other convenient manner.

It is obvious that a mere reversal of the cylinder and piston would be within the scope of my invention and would produce the same results. This and similar details are manifestly variable at the will of the constructor or mechanic and according to the conditions or exigencies of any given case.

What I claim is 1. In a band-saw mill, the combination of a main frame; a secondary frame mounted and guided therein and carrying the main saw supporting and stretching band-wheels; and a fluid-pressure motor connected with and serving to move the secondary frame relatively to the main frame, substantially as and for the purpose set forth.

2. In a band-saw mill, the combination of a main frame; a secondary frame movable relatively to the main frame and provided with upper and lower band-wheels to carry and stretch the saw; a fluid-pressure cylinder; and a piston, one of the last-mentioned parts being attached to and movable with the secondary frame and the other of said parts being fixed.

3. In a band-saw mill, the combination of a main frame; a secondary frame movable relatively to the main frame and provided with upper and lower saw-carrying wheels; a piston connected with the secondary frame; a fluid-pressure cylinder containing said piston; and a valve controlling admission and exhaust of pressure fluid to and from the space within the cylinder.

4. In combination with main frame 3, provided with guide rods or standards 6, 7, and 8; yokes 15 and 16, movable upon said rods or standards; band-wheel shafts carried by said yokes and provided with band-wheels; a cylinder; and a piston fitting within said cylinder and serving to elevate the yokes 15 and 16.

5. In a band-saw mill, the combination of guide rods or standards; two yokes or frames jointly andindependent-ly movable upon said guides or standards; shafts carried by said yokes; band-wheels carried by the shafts; and a screw interposed between and serving to vary the separation of said yokes.

6. In a band-saw mill, the combination of a main frame provided with suitable guides,

a two-part frame movable both jointly and independently upon said guides and relatively to the main frame; shafts and bandwheels carried one by each of the parts or sections of the movable frame; and means substantially as described for moving said framesections to varying distances from each other and holding them in their adjusted positions.

7. The combination in a band-saw mill, of vertically-adjustable yoke 16 provided with arm 25; sliding bracket 27 connected with said arm, box or hearing 29, carried upon the bracket; adjusting-screw 32 journaled in the bracket and threaded in the box or bearing; pinions 33 and 34; and shaft 35 passing through pinion 34 but engaging therewith to prevent rotation of the pinion and rod, substantially as set forth.

S. In a band-saw mill, the combination of yoke 16 provided with arm 25, bracket 27 oonnecti ng-rod '26 serving to adj ustably connect the arm and bracket, and boxes or bearings 29 and 30 carried by the yoke and the bracket, respectively; in combination with yoke 16, hanger 39 swiveled therein; box 30 pivotally supported in'said hanger; bracket 27 connected with an arm of the yoke, box or hearing 29 carried in said bracket; adj usting-screw 32, and pinions 33, 34 for moving said box laterally in or upon the bracket; and splined rod 35 for turning the pinion 34:, all substantially as shown In Witnesswhereof I hereunto set my hand in the presence of two witnesses.

EDNVARD E. FITZGERALD.

Witnesses:

B. T. LEUZARDER, B. A. BRENNAN. 

